Test cap unit for sealed fitting

ABSTRACT

A pipe fitting having an end wall and forming a port radially inwardly of the flange to align with the wall opening; an annular elastomeric seal positioned to be compressed between the wall and the work body wall for preventing leakage of fluid outwardly from the wall opening; a test cap unit spaced from the seal and aligned therewith to close off the opening and fastener structure extending through the cap unit and adjustably attached to the fitting for urging the cap unit into sealing relation with the inner side of the work body wall, about the opening, when the seal is compressed as aforesaid, whereby the cap unit then closes off the opening so that test liquid under pressure can be filled into the fitting to test for leakage; the cap unit having annular sealing structure facing toward the annular seal for sealing engagement with the wall inner side, the sealing structure comprising an elastomeric ring and the cap unit includes a plate carrying the ring, the ring consisting of resiliently deflectable material projecting from the plate. That material is typically sponge elastomer.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part Ser. No. 864,304 filed Apr.6, 1992, which is a continuation-in-part of Ser. No. 677,504 filed Mar.29, 1991.

This invention relates generally to testing of pipe joints and sealsused in plumbing applications; and more particularly, to pressuretesting the pipe flange seal used at the drain outlet of a bathtub orthe like, as well as associated pipe joints.

Pipe fittings, as used for drain purposes from bathtubs, require sealingagainst the tub wall to prevent leakage. Typically, compressible,annular, rubber seals are used between the fitting flanges and the outerside of the tub wall. Such seals require pressure testing duringinstallation to determine whether any leakage will develop duringoverflow draining of water from the tub. There is need for a simple,reliable method and means to quickly test such seals, as well as thepipe joints, against leakage.

SUMMARY OF THE INVENTION

It is a major object of the invention to provide improved method andmeans to meet the above need. Basically, the invention relates to acombination of elements applicable to a tub wall having an openingbetween its inner and outer sides, the combination including

a) a pipe fitting having an end wall, or flange, and forming a portradially inwardly of the flange to align with the wall opening,

b) an annular, elastomeric seal positioned to be compressed between theend wall or flange and the work body wall for preventing leakage offluid outwardly from the wall opening,

c) a test cap unit spaced from the seal and aligned therewith to closeoff the opening,

d) and fastener means extending through the cap unit and adjustablyattached to the fitting for urging the cap unit into sealing relationwith the inner side of the work body wall, about the wall opening, whenthe seal is compressed as aforesaid, whereby the cap unit then closesoff the opening so that liquid under pressure can be filled into thefitting to test for leakage.

Typically, the cap unit itself has an annular sealing means facingtoward the annular seal for sealing engagement with the wall inner side.That sealing means for example comprises an elastomeric o-ring, and thecap unit includes a plate carrying the o-ring. Also, the plate forms anannular groove in which a first annular part of the 0-ring is held, theo-ring including a second annular part protruding from the groove forsealing engagement with the inner side of the body wall. This allows theadjustable fastener means to protrude through the cap unit forconnection with the pipe fitting, without disturbing the annular seal.

As will be seen, the fastener means may include one of the following:

i) a single fastener, including a head engaging the plate defined by thecap unit, and a threaded shank penetrating into and threadably attachedto the pipe fitting;

ii) two fasteners, each including a head engaging the plate defined bythe cap unit, and a threaded shank penetrating into and threadablyattached to the fitting.

The invention also enables replacement of the test cap unit with a drainfitting cap installed at the inner side of the tub wall and attached bymeans of the same fastener means referred to. Another important featureof the invention is the provision for holding the fitting and seal inthe same precise alignment with the wall opening and wall as existedduring pressure testing, and during such replacement of the test capunit with a drain cap, ensuring proper sealing during final clamp-up.

A further object includes the provision of a test cap seal ring which isresiliently deflectable. It may consist of resiliently compressiblesponge elastomer; and, as will be seen, such a sponge ring typically hasaxial thickness between 3/8 inch and 3/4 inch. Also, such a ringfacilitates shifting adjustment of the cap, and may be compressed by thecap to greater extent at one side of the axis and to lesser extent atthe opposite side of the axis.

These and other objects and advantages of the invention, as well as thedetails of an illustrative embodiment, will be more fully understoodfrom the following specification and drawings, in which:

DRAWING DESCRIPTION

FIG. 1 is a vertical section taken through a device incorporating theinvention, and attached to a wall;

FIG. 2 is an enlarged frontal view of a test cap unit incorporating theinvention;

FIG. 3 is an enlarged fragmentary section taken on lines 3--3 of FIG. 2;

FIG. 4 is a fragmentary view like FIG. 1 but showing the test cap unitreplaced by a fixture drain cap;

FIG. 5 is a plan view showing a modified assembly like that of FIG. 1,but employing two fasteners to hold the test cap unit in position;

FIG. 6 shows an assembly incorporating the final drain cap;

FIG. 7 is a view like FIG. 1 showing provision and use of acompressible, elastomeric, sponge seal;

FIG. 8 is a frontal view of the seal, as shown in FIG. 7, and the capretaining it; and

FIG. 9 is an enlarged section taken on lines 9--9 of FIG. 8.

DETAILED DESCRIPTION

In FIGS. 1 and 21 a bathtub 10 has an end wall 11 extending downwardlyand inclined at an angle α as shown. An opening 12 is formed between theinner and outer wall surfaces 13 and 14 at an upper drain level.Normally, water 15 in the tub does not rise to the level opening 12;but, if it does, it passes through the opening to the pipe fitting andexternal drain pipe means for drainage. See such an external pipe 80 inFIG. 6, which extends vertically and is connected to short, horizontal,drain pipe 81 recessing drainage from a tube lower drain fitting 82.such pipes are typically made of plastic, joined together by adhesive atjoints 83.

The external pipe fitting 16 shown is in the form of an elbow having adrain passage 17. A fitting flange 18 extends about a port 19 registeredwith the tub wall opening 12, when installed. An annular, elastomericseal 20 is located between the flange 18 and the wall surface 14, aboutopening 12 for sealing off therebetween and preventing leakage of fluidoutwardly from opening 12 and outwardly of the fitting. The seal 20 maytypically have a wedge-shape in elevation, as shown, to enable desiredengagement with the outer surface 14 of wall 11. Projections 21,integral with flange 18, project toward wall 11 at circular locations toposition the bore 22 of the seal 20, locating the seal relative to theflange.

In accordance with the invention, a test cap unit 23 is spaced from theseal 20, at the inner side of wall 11, for closing off the opening 12.Also, fastener means is provided extending through the cap unit andadjustably attached to the fitting for urging the cap unit into sealingrelation with the inner side of the work body wall, about the opening,when the seal is compressed as aforesaid, whereby the cap unit thencloses off the opening 12 so that test liquid under pressure can befilled into the fitting 16 to test for leakage adjacent the elastomericseal 20. The seal, consisting of foam rubber, is compressed to reduceits thickness between about 25% to 50%. As shown, the fastener meanscomprises a single fastener 24, including a head 25, engaging a plate26, defined by the cap unit, and a shank 28 extending through an opening27 in the plate. The shank is threaded at 28a, for threadably engagingan internal thread 29 in a projection 30 integral with the body 31 ofthe fitting 16. Projection 30 extends in 17 toward opening 12, as seen.

The cap unit has an annular sealing means facing toward the annular sealfor sealing engagement with the wall inner side 13. As shown, thesealing means comprises an elastomeric o-ring 32 carried by the plate 26so that the o-ring sealingly engages inner surface 13 of wall 11 andextends about opening 12. When the fastener is tightened, the 0-ring 32compressively engages wall surface 13 to seal thereagainst; and the0-ring and plate 26 block escape of test fluid or liquid supplied underpressure (see arrow 36) to the interior 17 of the fitting. This allows apressure test of annular seal 20 from the bore side thereof, as desired,to determine if leakage exists between 20 and 18, or between 20 and 14.

FIG. 3 shows that plate 26 forms an annular groove 38 into which a firstpart of the 0-ring is received. The o-ring has a second annular part 32aprotruding from the groove for sealing engagement with wall surface 13.Groove 38 is formed between the annular protrusions 41 and 42, ensuringspacing of cap plate wall 26a from the tub wall 13. During a pressuretest, the tapered surface 25a of fastener head 25 sealingly engages therim of the opening 27 through plate 26, and also compensates for theadjustment angularity of the plate 26 relative to vertical, as shown.That angle is α.

A means to supply pressure fluid to the fitting interior 17 may compriseplastic pipe 80, adhesively joined to fitting bore 16b, at 85, to supplya desired head of liquid to the fitting interior 17 for the pressuretest.

FIG. 5 shows in plan view the alternate use of two fasteners 128,extending through a cap plate 126, corresponding to plate 26. Thefasteners have threaded shanks 128a threadably received in bores 129 inthe fitting body 170, as shown. See also seal 120 corresponding to seal20; and flange 118 corresponding to flange 18. The cap unit annular sealis shown at 132.

After completion of the pressure test, the cap unit 23 may be replacedby a drain cap 76 extending over the opening 12. Cap 76 has drain port77 to pass overflow liquid in the tub to the exterior fitting 16,connectible to drain plumbing. The same or like fastener means 24' maybe employed for connecting cap 76 to the projection 30 in FIG. 1.Equivalent dual fasteners may be used as in FIG. 5 to connect a draincap to the tub wall.

In use, the parts are made-up as for pressure test, as seen in FIG. 1;and thereafter, as seen in FIG. 6, the plastic pipes 80 and 81 are gluedtogether, as at joint 83; and pipe 80 is glued to fitting 17, asreferred to. Pipe 81 has been rigidly connected to the drain fitting 82,as via elbow 82a. This rigidizes the external piping, so that when testcap 23 is removed, as by withdrawing fastener 24, the seal 20 andfitting 16 remain in the same precise alignment with the wall 11 andwall surface imperfections. Then, when drain cap 76 is installed andfastener 24 or 24' is tightened, the seal will engage the wall surfaceimperfections in the same way, re-establishing the precision seal. Also,the adhesive joints are not disturbed or cracked during such finalattachment. The pipes 80 and 81, and/or joints at 83, 83', and 82a maybe metallic. System piping and trap piping is seen at 91 and 92.

Steps of the method of employing the invention include:

i) tightening the fastener means to compress the seal against the walland to clamp the test cap unit to the wall, closing the opening,

ii) connecting external piping to the fitting to rigidly support thefitting,

iii) applying water pressure internally of the piping and pipe fittingto test whether the elastomeric seal leaks,

iv) loosening the fastener means and removing the test cap unit, and

v) connecting a drain cap to the wall to cover the opening byretightening the fastener means to connect the cap to the fitting and tore-compress the seal.

Step ii) may include adhesively connecting the piping to the fitting andto drain fitting while the test cap unit remains clamped to the wall.

Further, in accordance with another aspect of the invention, steps i)and ii) are also carried out at a second work body wall opening using asecond pipe fitting and a second elastomeric seal; the step iii) is alsocarried out to test whether the second seal leaks, at the same time asthe first seal is tested.

In this way, a plurality of annular seals 20 at different locations in ahome or building may be simultaneously tested.

In FIG. 7, the assembly and elements are like those of FIG. 1, exceptthat the modified test cap unit 123 includes an elastomeric ring 132that consists of foamed or sponge elastomeric material, to beresiliently deflectable, allowing greater adjustability of plate 126.See for example greater compression at 132a, below fastener axis 160(and also below ring axis 161) than at 132b, above axis 160. The plate126 can therefore extend more nearly normal to the fastener axis 160.Adjustability to different angled walls 11 is thereby also facilitated,enhancing the function and benefits of the seal 20 at the outer side ofwall 11.

Cap plate 126 has an outer, annular flange 163 closely surrounding theouter, annular surface 164 of the ring furthest from the wall 11, toallow seal resilient compression, as described; and the plate 126 alsohas an annular series of shallow protrusions 165 extending close to theinner annular surface 166 of the ring farthest from wall 11, as shown.The flange 163 and protrusions 165 act to position the ring relative tothe plate, during assembly to FIG. 7 condition; and they allow extreme,differential, resilient compression of the ring, as described. Angularrelative shifting of the cap and fastener are also accommodated.

The axial thickness t₁ of the ring is typically between 3/8 inch and 3/4inch; and ring radial dimension t₂ between the ring bore 168 and outerperiphery 164, is typically between 3/8 inch and 3/4 inch. Thesedimensions are found to produce best results in terms of the functionsreferred to, for a ring whose overall diameter is between 21/2 inchesand 4 inches.

Ring 132 may be compressed, as referred to, to reduce its thicknessbetween about 25% to 60%, maximum other rings of lesser compressibilitymay be used.

I claim:
 1. In combination, for use with a work body wall having innerand outer sides, and an opening therethrough,a) a pipe fitting having anend wall and forming a port radially inwardly of the end wall to alignwith said wall opening, b) an annular elastomeric seal positioned to becompressed between said end wall and said work body wall for preventingleakage of fluid outwardly from said wall opening, c) a test cap unitspaced from said seal and aligned therewith to close off said opening,d) and fastener means extending through said cap unit and adjustablyattached to said fitting for urging the cap unit into sealing relationwith the inner side of said work body wall, about said opening, whensaid seal is compressed as aforesaid, whereby the cap unit then closesoff said opening so that test liquid under pressure can be filled intosaid fitting to test for leakage, e) said cap unit having annularsealing means facing toward the annular seal for sealing engagement withsaid wall inner side, said sealing means comprising an elastomeric ringand said cap unit includes a plate carrying said ring, said ringconsisting of resiliently deflectable material projecting from saidplate.
 2. The combination of claim 1 wherein said ring consists ofresiliently compressible sponge elastomer.
 3. The combination of claim 2wherein said plate has an outer, annular flange engaging the peripheryof said sponge elastomer ring to locate same relative to said fastener,the cap allowing relative angular shifting of the cap and fastener. 4.The combination of claim 2 wherein said plate forms an annular grooveinto which a first annular part of said ring is received, the ringincluding a second annular part protruding from said groove forcompressible sealing engagement with the inner side of said body wall.5. The combination of claim 1 wherein said fastener means protrudesthrough the cap unit.
 6. The combination of claim 5 wherein saidfastener means includes one of the following:i) a single fastener,including a head engaging the plate defined by the cap unit, and athreaded shank penetrating into and threadably attached to the fitting;ii) two fasteners, each including a head engaging the plate defined bythe cap unit, and a threaded shank penetrating into and threadablyattached to the fitting.
 7. The combination of claim 1 including saidwork body wall, the outer side of which is compressively engaged by saidseal, and the inner side of which is engaged by said cap unit to closeoff said wall opening.
 8. The combination of claim 7 including meanssupplying fluid under pressure to said fitting bore for testpressurizing said seal between said flange and said work body wall. 9.The combination of claim 1 wherein said seal consists of foamed,elastomeric material.
 10. The combination of claim 7 wherein said workbody wall is defined by a liquid container.
 11. The combination of claimI including pipe connected to said fitting to hold the seal and fittingin the same alignment with said wall and opening during replacement ofthe test cap with a drain cap, after said pressure test.
 12. Thecombination of claim 1 wherein said ring defines an axis and has axialthickness approximately equal to the radial dimension of the ringbetween a ring bore and a ring outer periphery.
 13. The combination ofclaim 1 wherein the ring defines an axis and has axial thickness between3/8 inch and 3/4 inch.
 14. The combination of claim 1 wherein the ringdefines an axis and is compressed by said cap greater extent at one sideof said axis and to lesser extent at the opposite side of said axes. 15.The combination of claim 13 wherein the seal has a radial dimensionbetween a bore and an outer periphery, said radial dimension beingbetween 3/8 inches and 3/4 inches, the ring overall diameter beingbetween 21/2 inches and 4 inches.
 16. The method incorporating thecombination of claim 1 and said wall, which includesi) tightening saidfastener means to compress said seal against said wall and to clamp thetest cap unit to said wall, closing said opening, ii) connectingexternal piping to said fitting to rigidly support the fitting, iii)applying water pressure internally of said piping and pipe fitting totest whether said elastomeric seal leaks, iv) loosening said fastenermeans and removing said test cap unit, and v) connecting a drain cap tosaid wall to cover said opening by retightening said fastener means toconnect the cap to said fitting and to re-compress said seal.
 17. Themethod of claim 16 wherein step ii) includes adhesively connecting saidpiping to said fitting and to a drain fitting while said test cap unitremains clamped to said wall.
 18. The method of claim 16 wherein saidsteps i) and ii) are also carried out at a second work body wall openingusing a second pipe fitting and a second elastomeric seal, said stepiii) is also carried out to test whether the second seal leaks, at thesame time as the first seal is tested.